Liquid ejection apparatus having marked belt

Abstract

A recording apparatus includes a recording unit recording an image, an endless belt which is stretched between rollers such that the inner circumferential surface thereof contacts the rollers and the outer circumferential surface thereof opposes the recording unit, a mark arranged on the profile of the belt, and a mark detection unit which detects that the mark moving in accordance with the travel of the belt is positioned at a predetermined position.

What is claimed is: 
     
       1. A recording apparatus comprising:
 a recording unit recording an image; 
 an endless belt stretched between a plurality of rollers so that an inner circumferential surface of the belt contacts the plurality of rollers whereas an outer circumferential surface of the belt opposes the recording unit; 
 a mark which is arranged on a profile of the belt; 
 a mark detection unit which detects that the mark moving in accordance with travel of the belt is positioned at a predetermined position, 
 wherein the mark has a reflectance different from a reflectance of the profile of the belt, and 
 wherein the mark detection unit is a reflective sensor which is provided to oppose the profile and has a light emitting unit and a light receiving unit; and 
 a control unit which increases a quantity of light emitted from the light emitting unit when a time during which the mark detection unit does not detect that the mark is at the predetermined position becomes greater than a predetermined time. 
 
     
     
       2. The recording apparatus according to  claim 1 , wherein, the predetermined position is a position close to one of the plurality of rollers. 
     
     
       3. The recording apparatus according to  claim 1 , wherein,
 the plurality of rollers include a drive roller and a driven roller, and 
 the predetermined position is a position upstream of the drive roller and downstream of the driven roller in a direction of travel of the belt. 
 
     
     
       4. The recording apparatus according to  claim 3 , further comprising:
 a tension roller which contacts the belt at a position downstream of the drive roller and upstream of the driven roller in the direction of the travel and adjusts the tension of the belt. 
 
     
     
       5. The recording apparatus according to  claim 3 , wherein
 the belt conveys the recording medium provided on the outer circumferential surface, when traveling from the driven roller to the drive roller, 
 the recording unit opposes the belt at a region upstream of the drive roller and downstream of the driven roller in the direction of the travel, and 
 the predetermined position is a position downstream of the region where the recording unit opposes the belt, in the direction of the travel. 
 
     
     
       6. A recording apparatus comprising:
 a recording unit recording an image; 
 an endless belt stretched between a plurality of rollers so that an inner circumferential surface of the belt contacts the plurality of rollers whereas an outer circumferential surface of the belt opposes the recording unit; 
 a mark which is arranged on a profile of the belt; 
 a mark detection unit which detects that the mark moving in accordance with travel of the belt is positioned at a predetermined position, 
 wherein the mark has a reflectance different from a reflectance of the profile of the belt, and 
 wherein the mark detection unit is a reflective sensor which is provided to oppose the profile and has a light emitting unit and a light receiving unit; 
 a belt position detection unit which detects a position of the belt in directions in which the profile of the belt and the light emitting unit move toward and away from each other; and 
 a control unit which increases a quantity of light emitted from the light emitting unit when a time during which the mark detection unit does not detect that the mark is at the predetermined position becomes greater than a predetermined time and the position of the belt detected by the belt position detection unit falls within a predetermined range. 
 
     
     
       7. A recording apparatus comprising:
 a recording unit recording an image; 
 an endless belt stretched between a plurality of rollers so that an inner circumferential surface of the belt contacts the plurality of rollers whereas an outer circumferential surface of the belt opposes the recording unit; 
 a mark which is arranged on a profile of the belt; 
 a mark detection unit which detects that the mark moving in accordance with travel of the belt is positioned at a predetermined position, 
 wherein the mark has a reflectance different from a reflectance of the profile of the belt, and 
 wherein the mark detection unit is a reflective sensor which is provided to oppose the profile and has a light emitting unit and a light receiving unit; 
 a belt position detection unit which detects a position of the belt in directions in which the profile of the belt and the light emitting unit move toward and away from each other; and 
 a control unit which moves the belt to be close to the light emitting unit when the position of the belt detected by the belt position detection unit is farther from the light emitting unit than a predetermined range and moves the belt away from the light emitting unit when the position of the belt is closer to the light emitting unit than the predetermined range, when a time during which the mark detection unit does not detect that the mark is at the predetermined position becomes greater than a predetermined time. 
 
     
     
       8. A recording apparatus comprising:
 a recording unit recording an image; 
 an endless belt stretched between a plurality of rollers so that an inner circumferential surface of the belt contacts the plurality of rollers whereas an outer circumferential surface of the belt opposes the recording unit; 
 a mark which is arranged on a profile of the belt; 
 a mark detection unit which detects that the mark moving in accordance with travel of the belt is positioned at a predetermined position, 
 wherein the mark has a reflectance different from a reflectance of the profile of the belt, and 
 wherein the mark detection unit is a reflective sensor which is provided to oppose the profile and has a light emitting unit and a light receiving unit; 
 a storage unit which stores sensor property information indicating a change in a detected signal value which is output from the light receiving unit in accordance with a change in the position of the belt; 
 a belt position detection unit which detects a position of the belt in directions in which the profile of the belt and the light emitting unit move toward and away from each other; and 
 a control unit which increases a quantity of light emitted from the light emitting unit when the detected signal value output from the light receiving unit is less than an expected signal value derived based on the position of the belt detected by the belt position detection unit and the sensor property information.